Use Align to align a control to the top, bottom, left, or right of a form or panel and have it remain there even if the size of the form, panel, or component that contains the control changes. When the parent is resized, an aligned control also resizes so that it continues to span the top, bottom, left, or right edge of the parent.

For example, to use a panel component with various controls on it as a tool palette, change the panel's Align value to alLeft. The value of alLeft for the Align property of the panel guarantees that the tool palette remains on the left side of the form and always equals the client height of the form.

The default value of Align is alNone, which means a control remains where it is positioned on a form or panel.

Tip: If Align is set to alClient, the control fills the entire client area so that it is impossible to select the parent form by clicking on it. In this case, select the parent by selecting the control on the form and pressing Esc, or by using the Object Inspector.

Any number of child components within a single parent can have the same Align value, in which case they stack up along the edge of the parent. The child controls stack up in z-order. To adjust the order in which the controls stack up, drag the controls into their desired positions.

Note: To cause a control to maintain a specified relationship with an edge of its parent, but not necessarily lie along one edge of the parent, use the Anchors property instead.

/*
This example shows how to use a splitter to divide a form
into resizable panes. All objects on the form are created
dynamically in the OnCreate event handler of the form. To
run this example, add ExtCtrls and FileCtrl to the uses
clause of the form’s implementation section.
Note that when creating a splitter dynamically at runtime,
it is important to set its position to the appropriate side
of the control it will resize.
*/void__fastcall TForm1::FormCreate(TObject *Sender)
{
TSplitter* ps = new TSplitter(Form1); // These objects will all be cleaned up by the owner (Form1).TFileListBox* pflb = newTFileListBox(Form1); // The parent (Form1) will clean up these objects.TDirectoryListBox* pdlb = newTDirectoryListBox(Form1);
// Line up the directory list box on the left of the form.
pdlb->Parent = Form1;
pdlb->Align = alLeft;
pdlb->Width = Form1->ClientWidth/3;
// Now use the splitter to divide the directory pane from the file pane.
ps->Parent = Form1;
ps->Left = pdlb->Left + pdlb->Width + 1; // Move to right of directory list.
ps->Align = pdlb->Align; // Give same alignment as directory list.// Each pane must be at least one quarter of the form's width.
ps->MinSize = Form1->ClientWidth/4;
// Finally, create the last pane - a file list box.
pflb->Parent = Form1;
pflb->Align = alClient;
pdlb->FileList = pflb; // Link the file list box to the directory list box.
}

{
This example shows how to use a splitter to divide a form
into resizable panes. All objects on the form are created
dynamically in the OnCreate event handler of the form. To
run this example, add ExtCtrls and FileCtrl to the uses
clause of the form’s implementation section.
Note that when creating a splitter dynamically at runtime,
it is important to set its position to the appropriate side
of the control it will resize.
}procedure TForm1.FormCreate(Sender: TObject);
var
Split: TSplitter;
Files: TFileListBox;
Dirs: TDirectoryListBox;
begin{ first add a directory list box to the form }
Dirs := TDirectoryListBox.Create(Form1);
{ line it up on the left of the form }
Dirs.Parent := Form1;
Dirs.Align := alLeft;
Dirs.Width := Form1.ClientWidth div 3;
{ now add the splitter to divide the directory pane from the file pane }
Split := TSplitter.Create(Form1);
Split.Parent := Form1;
{ make sure the splitter is to the right of the directory list box! }
Split.Left := Dirs.Left + Dirs.Width + 1;
Split.Align := Dirs.Align; { give it the same alignment as the directory }{ each pane must be at least one quarter of the form’s width }
Split.MinSize := Form1.ClientWidth div 4;
{ Finally, create the last pane – a file list box }
Files := TFileListBox.Create(Form1);
Files.Parent := Form1;
Files.Align := alClient;
Dirs.FileList := Files; { link the file list box to the directory list box }end;